I have just done the following again: Help > Check for Updates, but no updates have been found.

I gather from the build path that the intellisense extracts the data from E:\Program Files\android-sdks\platforms\android-15\android.jar. I examined android.jar, and everything in it looks normal. Class View is there. The only difference this class has from others is its large size (10KB). Most other classes are smaller than 1KB.

I am running Windows 7 Ultimate 64-bit on a quad-core machine. The capacity of the machine should not be a problem.

I can advise you to perform the below steps:
1. Download a fresh android SDK and re-install it
2. Download the latest eclipse version (I think Indigo)
3. Do all the updates of your plugins as you did before